


He walks like an angel, but he's the Devil in disguise

by Thebicirclegirl



Category: Supernatural
Genre: Aunt Amara (Supernatural), Casifer, Castiel and Dean Winchester Have a Profound Bond, Castiel and Dean Winchester in Love, Castiel is Protective of Dean Winchester, Castiel is a Winchester (Supernatural), Destiel - Freeform, Established Castiel/Dean Winchester, Life in the bunker, Lucifer is So Done (Supernatural), M/M, Married Destiel, Men of Letters Bunker (Supernatural), Post-Mark of Cain (Supernatural), establised destiel, supernatural season 11
Language: English
Status: In-Progress
Published: 2020-03-25
Updated: 2020-03-25
Packaged: 2021-02-28 23:54:07
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,595
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23305627
Author URL: https://archiveofourown.org/users/Thebicirclegirl/pseuds/Thebicirclegirl
Summary: When Castiel does the unthinkable and says yes to be Lucifer's vessel, he couldn't have imagined just how awful things would become when the devil would use his love of Dean against him for his own amusement.
Relationships: Castiel/Dean Winchester
Comments: 8
Kudos: 28





	He walks like an angel, but he's the Devil in disguise

It had only been a few days since Castiel had said the big 'yes' to Lucifer to make the devil spare the Winchesters but for the seraph it had felt more like decades. This stupid selfless sacrifice was tried and true Winchester brand of stupid behaviour and it really signalled that the Angel was truly part of the family now.

"What are you doing" Cass said groggily, hazing in and out of consciousness whist trapped in his own mind.

Lucifer was watching the bunker's security footage tapes on a VHS machine he had found collecting dust in one of the hundreds of cupboards in the Men of Letters Bunker. Sure he had initially been looking for something more exciting than tapes of his enemies daily life's. Like maybe some of those angelic weapons Cass's next in command Balthazar had stolen during his little civil war against Raphael but hey Devils can't be chosers. Although, out of any place on the country he would have assumed the Men of Letters would have procured a flaming sword or a specially crafted lance at some point but the majority of weapons he came across where just the blades of the countless Angels the Winchesters and their lap dog had taken on during the years. He'd just have to find something else to help him get the upper hand on the Darkness. Anyways it was quite entertaining to watch the tape of Dean beating the ever loving crap out of Castiel when he was all jacked up on the Mark of Cain on repeat. Especially when he knew the Angel in question had no where to go to avoid reliving this painful memory over and over again. Some people are just naturally talent and inflicting pain whether it be physical or psychological was Lucifer's God given talent. 

"This is a hoot wow he's so alpha isn't he Cass?" Lucifer said to the Angel, halfway through his second bowl of popcorn that day. He didn't need to eat of course he just enjoyed the dramatics of it all.

Castiel was practically fuming "You were supposed to help us defeat the Darkness, not just sit back and watch security footage all day Lucifer" Cass snarled at him.

"Relax I'll get to auntie Amara baby bro don't worry yourself, I'm just weighing up my pros and for now I might as well play catch up as to what you bozos were up to in my absence" He chided the seraph. "This is more entertaining than the Kardashians" Lucifer added as he threw a handful of popcorn into his mouth.

Just then, the Devils binge watching session was interrupted by the clanking of the heavy metal door of the bunker, signalling the return of Castiel's favourite hunter back home.

The echoing of "Cass!" could be heard throughout the halls of the bunker as the hunter searched for the Angel.

"Oh here we go, it's show time" Lucifer stretched his arms out and prepared to lower his voice around three octaves to achieve that correct level of angelic constipation that Cass's normal speaking voice has.

"Speaking of your squeeze" He mocked the Angel he was sharing a vessel with as Dean stormed into the room.

"Hello Dean" He said, as he began his charade as the Angel for the hunter once again.

"Don't 'hello Dean, me" The elder Winchester was clearly drunk as the aroma of cheap beer wafted around him. "Where the fuck were you?" He sounded rightly pissed off.

"I'm sorry" Casifer pulled that confused puppy head tilt Cass so often does.

"Sorry isn't gonna cut it Sunshine. I sat in the restaurant for an hour and the guy at the bar thought I got stood up and gave me a free beer. Well I guess I did actually get stood up. Getting stood up is bad enough but at that restaurant, we waited weeks for the reservation and now I can't ever go back there man I'm humiliated" Dean huffed, clearly very upset with the Angel.

"Restaurant?" The word left Cass's lips which weren't being piloted by him.

Dean rolled his eyes tiredly "Cass remind me again what day is it?" He asked calmly.

"Thursday" The devil in disguise replied very matter of factly.

"Yeah and what is it that we do on Thursdays?" Dean said plainly.

He blanked "Uhhhh is it laundry day?" Lucifer went out on a limb.

"Oh my god I can't believe you right now. You're the Angel of Thursday but you can't remember what we do on a Thursday?" That's so ironic" Dean was definitely starting to fly off the handle.

Fuck he thought that could have been it what else do these stupid humans do then? "Dean what is wrong, what did I forget?" Lucifer asked the hunter as they began to wonder could he nominate himself for an Oscar for his outstanding performance as Castiel, which was still fooling his human pet so successfully.

"It's date night you dick" Dean erupted shouting at Castiel.

Lucifer couldn't believe his ears. Dean and Castiel were an item as he has suspected for so long. Actually hearing confirmation of this fact was giving him one hundred and one terribly delightful way to toy with the hunter and the Angel. He should have know when the hunter came in the door. He wasn't wearing his usual hillbilly flannel, the hunter had actually scrubbed up quite well. He had his hair styled and was even wearing a fancy button up and shoes that didn't look like they had monster gunk on them at some point, you could even say he looked handsome tonight.

"Dean I'm so sorry it totally escaped my mind" They tried to play it off unsuccessfully.

"Is this you being pissy because Amara kissed me? Your aunt is a bit of a cougar sure but look I already told you she means nothing to me! It's that stupid mark Cain crap, it's like a goddamn tramp stamp" He threw the suit jacket he had been carrying in his arms onto the chair at the war room table.

"She feels connected to you because you bore the mark Dean" The archangel assessed the situation.

"Yeah but she ain't my type no offence. Number one older than the planet and also she's my husbands aunt it's not a turn on at all!" Dean assured them, gesturing to Cass at the word 'husband'.

Just then Lucifer realised the presence of the matching gold bands on the hunter and the Seraph's fingers. Oh this day keeps getting better and better he thought to himself.

"Anyway I'm going to sleep I'll see you tomorrow your highness, which will be Friday. Hope you understand how the days of the week work by then. Don't even try and come to bed because I'm still pissed at you. I'm whacking up a warding sigils in my room you can have the couch" Dean yelled as he tried to storm off dramatically, but his drunken legs weren't given him the best attempt at it.

"Baby bro congrats on the matrimony!" Lucifer began to pester Castiel as soon as Dean is out of the room with this new information at his disposal.

"Shut up" Castiel cautioned the other inhabitant of his vessel.

"No really tying the knot that's a big moment in someone's life, so when we are we gonna hear the pitter patter of Nephilim feet? Sure you'd have to change to a female vessel but I'm sure Dean wouldn't mind my bi-dar is dinging" The Devil remarked.

"Don't hold your breath I much prefer this vessel than my last" Cas said as they recalled the amount of annoyance they faced when they sported a female vessel back in 1901. He didn't particularly feel like being in another female visage for the foreseeable future when bras existed. What torturous devices, they were clearly an output of Hell.

"Why not! That kid would be a chip off the old block, an alcohol dependency and a saviour complex before their ten sounds like a blast to me. Look I'd even be the godfather since we're so close now practically inseparable I'd say" Lucifer practically beamed.

"That's not what I meant. Never mind why am I even humouring your idiocy" Cass spat back at him.

"Now that was mean cassie! Wait oh my dad, lightbulb moment Dean's a bottom. Oh it all makes sense now that macho man front it's all a facade" Satan rubbed his face in his moment of realisation.

"Watch you damn mouth" Cass's blood was beginning to boil with anger.

"Aww an angry hubby Cass how sweet, does Samantha know about you two love birds?" He inquired cheekily.

"What-no and I solely agreed to let you share my vessel to spare Sam. I certainly didn't consent to you wreaking havoc in my personal affairs Lucifer and it's none of your business frankly" Castiel sneered at the Devil.

"That's your problem not mine pal, what's yours is mine su casa mi casa" Lucifer grinned to himself.

"I swear if you hurt him in any way I so help me" Cass threatened them, his voice shaking with anger.

"What you gonna do huh? Cass your just a run of the mill Angel me? I'm one of the big cheeses  
Don't worry I'll take good care of him" Lucifer assured the younger Angel, as he smirked evilly.

That wording made Castiel beyond terrified for what was to come, and he definitely should have been. If he only knew what ideas Lucifer had brewing in his twisted mind...

**Author's Note:**

> This is what I do during the big corona terror after watching the new episode who knows how long it'll be before we get the rest of season 15 so for now I'll entertain myself by writing fic, hope this is enjoyable for someone else apart from me out there!
> 
> Wash your hands and stay safe everyone <3
> 
> For updates follow my tumblr: @onesassyvessel


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